Frequency band determination based on image of communication environment for head-mounted display

ABSTRACT

Methods and apparatus provide for: continuously acquiring information of an environment in which at least one of a communication device and a communication partner for the communication device is placed; and upon the acquisition of each information, determining from among a plurality of communication standards of frequency bands of radio waves, and based on the acquired information, the communication standard to be used for communication between the communication device and the communication partner, where the communication partner outputs video and audio signals to the communication device, continuously acquiring includes continuously acquiring the information at a predetermined frame rate, and the communication device includes at least one camera.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. Pat. Application No.17/224,470, accorded a filing date of Apr. 7, 2021, allowed; which is acontinuation application of U.S. Pat. Application No. 16/903,682,accorded a filing date of Jun. 17, 2020 (U.S. Pat. 10,999,847 issued onMay 4, 2021); which is a continuation application of U.S. Pat.Application No. 15/776,242, accorded a filing date of May 15, 2018 (U.S.Pat. 10,721,735 issued on Jul. 21, 2020); which is a national stageapplication of International Application No. PCT/JP2016/087749, filedDec. 19, 2016; which claims priority to JP Application No. 2015-251360,filed Dec. 24, 2015, the entire disclosures of which are herebyincorporated by reference.

TECHNICAL FIELD

The present invention relates to a frequency band determination device,a head-mounted display, a frequency band determination method, and aprogram.

BACKGROUND ART

There is a known technology for monitoring radio wave conditions forwireless communication and changing a frequency band used forcommunication in accordance with the monitored radio wave conditions.

SUMMARY TECHNICAL PROBLEM

Millimeter waves, for example, in a 60 GHz band are highly linear. Thus,the communication quality of such millimeter waves significantly variesdepending on an environment in which a communication device and acommunication partner are placed, namely, for example, depending onwhether an obstacle exists in a communication path or the communicationdevice and the communication partner are in the same room. It istherefore preferable that the frequency band used for communication bechanged as soon as possible in accordance with a change in theenvironment in which the communication device and the communicationpartner are placed.

If, for example, the radio waves used for communication by thecommunication device are changed to 5 GHz band or other microwaves in asituation where the communication quality degrades while thecommunication device uses millimeter waves for communication, thecommunication quality may improve because the microwaves are morediffractive than the millimeter waves. Therefore, if the communicationquality is lowered while millimeter waves are used for communication, itis preferable that the radio waves used for communication by thecommunication device be changed to microwaves as soon as possible.

Consequently, when the communication quality of millimeter-wavecommunication is monitored and found to be degraded, it is conceivablethat an attempt is made to change the radio waves for communication bythe communication device to microwaves. However, if such an approach isused, a certain period of time elapses between the instant at which anenvironmental change occurs to degrade the communication quality and theinstant at which the radio waves used for communication by thecommunication device are changed to microwaves.

The present invention has been made in view of the above circumstances.An object of the present invention is to provide a frequency banddetermination device, a head-mounted display, a frequency banddetermination method, and a program that are capable of unprecedentedlyquickly changing the frequency band used for communication in accordancewith a change in the environment in which the communication device andthe communication partner are placed.

Solution to Problem

In order to solve the above problem, a frequency band determinationdevice according to the present invention includes an image acquisitionsection and a frequency band determination section. The imageacquisition section acquires an image of an environment in which atleast either a communication device or a communication partner for thecommunication device is placed. The frequency band determination sectiondetermines, based on the acquired image, the frequency band of radiowaves used for communication between the communication device and thecommunication partner.

According to an aspect of the present invention, the frequency banddetermination section determines the frequency band depending on whetheror not the communication device and the communication partner are in thesame room.

Alternatively, the frequency band determination section may determinethe frequency band depending on whether the acquired image includes animage of the communication device or an image of the communicationpartner.

Still alternatively, the frequency band determination section determinesthe frequency band in accordance with the distance between thecommunication device and the communication partner, which isidentifiable from the acquired image.

In this aspect, if the distance is greater than a first threshold value,the frequency band determination section may change the frequency bandfrom a first frequency band to a second frequency band; if the distanceis smaller than a second threshold value, the frequency banddetermination section may change the frequency band from the secondfrequency band to the first frequency band; the first threshold valuemay be greater than the second threshold value; the first frequency bandmay be higher than the second frequency band; and the difference betweenthe second threshold value and the first threshold value may be based onthe distance.

A head-mounted display according to the present invention includes animage acquisition section and a frequency band determination section.The image acquisition section acquires an image of an environment inwhich at least either the head-mounted display or a communicationpartner for the head-mounted display is placed. The frequency banddetermination section determines, based on the acquired image, thefrequency band of radio waves used for communication between thehead-mounted display and the communication partner.

A frequency band determination method according to the present inventionincludes the steps of: acquiring an image of an environment in which atleast either a communication device or a communication partner for thecommunication device is placed; and determining, based on the acquiredimage, the frequency band of radio waves used for communication betweenthe communication device and the communication partner.

A program according to the present invention causes a computer toexecute procedures for: acquiring an image of an environment in which atleast either a communication device or a communication partner for thecommunication device is placed; and determining, based on the acquiredimage, the frequency band of radio waves used for communication betweenthe communication device and the communication partner.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating an exemplary overall configuration of avideo display system according to an embodiment of the presentinvention.

FIG. 2A is a diagram illustrating an exemplary configuration of ahead-mounted display according to an embodiment of the presentinvention.

FIG. 2B is a diagram illustrating an exemplary configuration of a relaydevice according to an embodiment of the present invention.

FIG. 3A is a schematic diagram illustrating an example in which thevideo display system according to the present embodiment is disposed ina room.

FIG. 3B is a schematic diagram illustrating an example in which thevideo display system according to the present embodiment is disposed ina room.

FIG. 4 is a functional block diagram illustrating examples of functionsimplemented in the head-mounted display according to an embodiment ofthe present invention.

FIG. 5 is a flowchart illustrating exemplary processing steps performedby the head-mounted display according to an embodiment of the presentinvention.

FIG. 6 is a flowchart illustrating exemplary processing steps performedby the head-mounted display according to an embodiment of the presentinvention.

DESCRIPTION OF EMBODIMENT

An embodiment of the present invention will now be described withreference to the accompanying drawings.

FIG. 1 is a diagram illustrating an exemplary overall configuration of avideo display system 10 according to an embodiment of the presentinvention. FIG. 2A is a diagram illustrating an exemplary configurationof a head-mounted display (HMD) 12 according to the present embodiment.FIG. 2B is a diagram illustrating an exemplary configuration of a relaydevice 16 according to the present embodiment.

As illustrated in FIG. 1 , the video display system 10 according to thepresent invention includes the HMD 12, an entertainment device 14, therelay device 16, a display 18, a camera/microphone unit 20, and acontroller 22.

As illustrated, for example, in FIG. 2A, the HMD 12 according to thepresent embodiment includes a control section 30, a storage section 32,two communication sections 34 (first communication section 34 a andsecond communication section 34 b), an input/output section 36, adisplay section 38, a sensor section 40, an audio output section 42, anda camera section 44.

The control section 30 is formed of a microprocessor or other programcontrol device that operates in accordance, for example, with a programinstalled on the HMD 12.

The storage section 32 is formed of a storage element such as aread-only memory (ROM) or a random access memory (RAM). The storagesection 32 stores, for example, a program that is to be executed by thecontrol section 30.

The first communication section 34 a and the second communicationsection 34 b are each formed of a wireless local area network (LAN)module or other communication interface having a built-in array antenna.As illustrated in FIG. 1 , the present embodiment is configured so thatthe first communication section 34 a and the second communicationsection 34 b are disposed on the upper front of the HMD 12.

In the present embodiment, the communication standard for communicationestablished by the first communication section 34 a is different fromthe communication standard for communication established by the secondcommunication section 34 b. For example, the first communication section34 a establishes 60 GHz band communication, whereas the secondcommunication section 34 b establishes 5 GHz band communication.

The 60 GHz band communication provides communication at a higher maximumrate than the 5 GHz band communication. Further, the 60 GHz bandcommunication provides higher linearity and a shorter communicationrange than the 5 GHz band communication. In the present embodiment,either the first communication section 34 a or the second communicationsection 34 b can be selectively used to communicate with the relaydevice 16 in accordance with radio wave conditions for wirelesscommunication. Further, a well-known adaptive modulation/codingtechnology can be used in the present embodiment to adaptively changethe modulation method and coding method of the first and secondcommunication sections 34 a and 34 b in accordance with the radio waveconditions for wireless communication.

The input/output section 36 is formed of an input/output port such as anHDMI (registered trademark) (High-Definition Multimedia Interface) port,a universal serial bus (USB) port, or an auxiliary (AUX) port.

The display section 38 is formed of a liquid-crystal display, an organicelectroluminescence (EL) display, or other display disposed on the frontof the HMD 12, and used to display, for example, video generated by theentertainment device 14. The display section 38 is accommodated in ahousing of the HMD 12. The display section 38 may receive, for example,a video signal outputted from the entertainment device 14 and relayed bythe relay device 16, and output video represented by the received videosignal. The display section 38 according to the present embodiment iscapable of displaying a three-dimensional image, for example, bydisplaying a left-eye image and a right-eye image. The display section38 may be capable of displaying only a two-dimensional image andincapable of displaying a three-dimensional image.

The sensor section 40 is formed of a sensor such as an accelerationsensor or a motion sensor. The sensor section 40 outputs the results ofmeasurements, such as a rotation amount and movement amount of the HMD12, to the control section 30 at a predetermined frame rate.

The audio output section 42 is formed, for example, of a headphone or aspeaker, and used to output, for example, a sound that is represented byaudio data generated by the entertainment device 14. The audio outputsection 42 receives, for example, an audio signal outputted from theentertainment device 14 and relayed by the relay device 16, and outputsa sound represented by the received audio signal.

The camera section 44 is formed of a digital camera or other camera andused to capture, at a predetermined frame rate, an image of surroundingsof a user wearing the HMD 12. As illustrated in FIG. 1 , the camerasection according to the present embodiment includes, for example, fourcameras. As depicted, for example, in FIG. 1 , the four cameras areindividually disposed on the upper left of the display section 38, theupper right of the display section 38, the left side surface of thehousing for the HMD 12, and the right side surface of the housing forthe HMD 12. The cameras may incorporate, for example, a fisheye lens tocapture an omnidirectional image of the surroundings of the HMD 12 ormay be capable of capturing only a directional image. Further, thecamera section 44 may include an infrared camera that is disposed insidethe housing for the HMD 12 to detect the line-of-sight direction of theuser wearing the HMD 12.

Furthermore, the camera section 44 may be capable of identifying thedistance between the HMD 12 and the relay device 16. For example, thecameras disposed on the upper left and upper right of the displaysection 38 may be configured as a stereo camera. Moreover, the distancebetween the HMD 12 and the relay device 16 may be identifiable based onan image captured by the stereo camera. In addition, the camera section44 may include an infrared camera or other device (distance measuringdevice) capable of measuring the distance between the HMD 12 and therelay device 16, which is disposed forward of the HMD 12.

The entertainment device 14 according to the present embodiment isformed of a computer such as a game console, a digital versatile disc(DVD) player, or a Blu-ray (registered trademark) player. Theentertainment device 14 according to the present embodiment generatesvideo and audio, for example, by executing a stored game program orreproducing content recorded on an optical disk. The entertainmentdevice 14 according to the present embodiment outputs a video signalrepresentative of the generated video and an audio signal representativeof the generated audio to the HMD12 and the display 18 through the relaydevice 16.

The relay device 16 according to the present embodiment is formed of acomputer that relays the video and audio signals outputted from theentertainment device 14 and outputs them to the HMD 12 and the display18.

As illustrated, for example, in FIG. 2B, the relay device 16 accordingto the present embodiment includes a control section 50, a storagesection 52, two communication sections 54 (first communication section54 a and second communication section 54 b), and an input/output section56.

The control section 50 is formed, for example, of a control circuit or acentral processing unit (CPU) or other program control device thatoperates in accordance with a program installed on the relay device 16.

The storage section 52 is formed, for example, a ROM, a RAM, or otherstorage element. The storage section 52 stores, for example, a programto be executed by the control section 50.

The first communication section 54 a and the second communicationsection 54 b are each formed of a wireless LAN module or othercommunication interface having a built-in array antenna. As illustratedin FIG. 1 , the present embodiment is configured so that the firstcommunication section 54 a and the second communication section 54 b areincluded in the front of the relay device 16.

In the present embodiment, the communication standard for communicationestablished by the first communication section 54 a is different fromthe communication standard for communication established by the secondcommunication section 54 b. For example, the first communication section54 a establishes 60 GHz band communication, whereas the secondcommunication section 54 b establishes 5 GHz band communication.

As mentioned earlier, the 60 GHz band communication providescommunication at a higher maximum rate than the 5 GHz bandcommunication. Further, the 60 GHz band communication provides higherlinearity and a shorter communication range than the 5 GHz bandcommunication. In the present embodiment, either the first communicationsection 34 a or the second communication section 34 b can be selectivelyused to communicate with the HMD 12 in accordance with the radio waveconditions for wireless communication.

The input/output section 56 is formed of an input/output port such as anHDMI (registered trademark) (High-Definition Multimedia Interface) portor a USB port.

The display 18 according to the present embodiment is formed, forexample, of a liquid-crystal display, and used to display, for example,video represented by a video signal outputted from the entertainmentdevice 14.

The cameralmicrophone unit 20 according to the present embodimentincludes a camera 20 a and a microphone 20 b. The camera 20 a capturesan image, for example, of a subject and outputs the captured image tothe entertainment device 14. The microphone 20 b captures an ambientsound, converts the captured sound to audio data, and outputs the audiodata to the entertainment device 14. Further, the camera 20 a accordingto the present embodiment is a stereo camera.

The HMD 12 and the relay device 16 are capable of establishing, forexample, wireless communication to send and receive data to and fromeach other. When the HMD 12 and the relay device 16 communicate witheach other in the present embodiment, 60 GHz band communication isestablished between the first communication section 34 a and the firstcommunication section 54 a, and 5 GHz band communication is establishedbetween the second communication section 34 b and the secondcommunication section 54 b.

The entertainment device 14 is connected to the relay device 16, forexample, with an HDMI cable or a USB cable. The relay device 16 isconnected to the display 18, for example, with an HDMI cable. Theentertainment device 14 is connected to the cameralmicrophone unit 20,for example, with an AUX cable.

The controller 22 according to the present embodiment is an operationinput device that is used to make an operation input to theentertainment device 14. The user can use the controller 22 to performvarious operation input procedures by pressing a direction key or abutton on the controller 22 or tilting an operating stick on thecontroller 22. Then, in the present embodiment, the controller 22outputs to the entertainment device 14 input data associated with theoperation input. Further, the controller 22 according to the presentembodiment includes a USB port. When connected to the entertainmentdevice 14 with a USB cable, the controller 22 is capable of outputtinginput data to the entertainment device 14 in a wired manner. Thecontroller 22 according to the present embodiment additionally includes,for example, a wireless communication module, and is thus capable ofwirelessly outputting input data to the entertainment device 14.

FIGS. 3A and 3B are schematic diagrams illustrating examples in whichthe video display system 10 according to the present embodiment isdisposed in a room. In the present embodiment, the first communicationsection 34 a of the HMD 12 establishes 60 GHz band communication withthe first communication section 54 a of the relay device 16 when the HMD12 and the relay device 16 are in the same room as illustrated in FIG.3A. Meanwhile, when the HMD 12 and the relay device 16 are in differentrooms as illustrated in FIG. 3B, the second communication section 34 bof the HMD 12 establishes 5 GHz band communication with the secondcommunication section 54 b of the relay device 16.

Based on an image that is captured by the camera section 44 to depict anenvironment in which at least either the HMD 12 or the relay device 16is placed, the present embodiment determines whether the HMD 12 and therelay device 16 are in the same room or in different rooms. If, forexample, an image of the relay device 16 is included in the imagecaptured by the camera section 44, it is determined that the HMD 12 andthe relay device 16 are in the same room. If, by contrast, the image ofthe relay device 16 is not included in the image captured by the camerasection 44, it is determined that the HMD 12 and the relay device 16 arein different rooms.

If it is determined that the HMD 12 and the relay device 16 are in thesame room, the present embodiment exercises control so as to establish60 GHz band communication between the HMD 12 and the relay device 16.If, by contrast, it is determined that the HMD 12 and the relay device16 are in different rooms, the present embodiment exercises control soas to establish 5 GHz band communication between the HMD 12 and therelay device 16.

As described above, based on the positional relationship between the HMD12 and the relay device 16, which is identified from an image capturedby the camera section 44, the present embodiment determines thefrequency band of radio waves used for communication.

When the HMD 12 and the relay device 16 are in different rooms, there isa wall, a door, or other obstacle between the HMD 12 and the relaydevice 16. Therefore, it is highly probable that 60 GHz or otherhigh-frequency band communication is low in quality. Consequently, whenit is determined based on an image captured by the camera section 44that the HMD 12 and the relay device 16 are in different rooms, thepresent embodiment exercises control so as to establish 5 GHz or otherlow-frequency band communication between the HMD 12 and the relay device16. Let us assume, for example, that the user wearing the HMD 12 movesfrom a room in which the relay device 16 is disposed to another roomwhile 60 GHz band communication is established between the HMD 12 andthe relay device 16. In this instance, the communication between the HMD12 and the relay device 16 switches to 5 GHz band communication. In thismanner, the present embodiment changes the frequency band of radio wavesused for communication in accordance with a change in the environment inwhich the HMD 12 and the relay device 16 are placed, and this changeoccurs earlier than a frequency band change after communication qualityconfirmation.

Further, millimeter waves are advantageous in that, for example, themaximum rate available for communication is high. Therefore, if thecommunication quality provided by the millimeter waves is achievableduring microwave communication, it is preferable that microwavecommunication be replaced by millimeter-wave communication. Let usassume here that while 5 GHz band communication is established betweenthe HMD 12 and the relay device 16, a user wearing the HMD 12 moves froma room to another room in which the relay device 16 is disposed. In thisinstance, the communication between the HMD 12 and the relay device 16switches to 60 GHz band communication. In this manner, the presentembodiment switches to high-frequency band communication in accordancewith an environmental change that improves the quality of high-frequencyband communication.

Meanwhile, whether an obstacle exists between the HMD 12 and the relaydevice 16 to block radio waves may be determined based on an imagecaptured by the camera section 44. If it is determined that an obstacleexists between the HMD 12 and the relay device 16 to block radio waves,control may be exercised so as to establish 5 GHz band communicationbetween the HMD 12 and the relay device 16. If, by contrast, it isdetermined that no obstacle exists between the HMD 12 and the relaydevice 16 to block radio waves, control may be exercised so as toestablish 60 GHz band communication between the HMD 12 and the relaydevice 16.

Further, even if the HMD 12 and the relay device 16 are in the sameroom, the frequency band of radio waves used for communication may bedetermined depending on whether an image of the relay device 16 isincluded in an image captured by the camera section 44. If, for example,the image of the relay device 16 is included in the image captured bythe camera section 44, control may be exercised so as to establish 60GHz band communication between the HMD 12 and the relay device 16.Meanwhile, if, for example, the image of the relay device 16 is notincluded in the image captured by the camera section 44, control may beexercised so as to establish 5 GHz band communication between the HMD 12and the relay device 16.

Moreover, whether 5 GHz or 60 GHz band communication is to beestablished between the HMD 12 and the relay device 16 may be determinedin accordance, for example, with the distance between the HMD 12 and therelay device 16. In such an instance, the distance between the HMD 12and the relay device 16 may be identified by the stereo camera includedin the camera section 44. If the HMD 12 includes a distance measuringdevice, the distance measuring device may identify the distance betweenthe HMD 12 and the relay device 16.

Functions of the HMD 12 according to the present embodiment and aprocess performed by the HMD 12 will be further described below. The HMD12 according to the present embodiment functions as a frequency banddetermination device that determines the frequency band of radio wavesused for communication between the HMD 12 and the relay device 16 inaccordance with an environment in which at least either the HMD 12 orthe relay device 16 is placed.

FIG. 4 is a functional block diagram illustrating examples of functionsimplemented in the HMD 12 according to the present embodiment. The HMD12 according to the present embodiment need not incorporate all thefunctions illustrated in FIG. 4 , and may incorporate functions otherthan those illustrated in FIG. 4 .

As illustrated in FIG. 4 , the HMD 12 according to the presentembodiment functionally includes an image acquisition section 60, afrequency band determination section 62, and a communication controlsection 64. The image acquisition section 60 is mainly implemented bythe control section 30 and the camera section 44. The frequency banddetermination section 62 is mainly implemented by the control section30. The communication control section 64 is mainly implemented by thecontrol section 30, the first communication section 34 a, and the secondcommunication section 34 b.

The above functions may be implemented by allowing the control section30 to execute a program that is installed on the HMD 12 formed of acomputer and includes commands for the above functions. The program issupplied to the HMD 12, for example, through an optical disk, a magneticdisk, a magnetic tape, a magneto-optical disk, a flash memory, or othercomputer-readable information storage medium or through the Internet orthe like.

In the present embodiment, the image acquisition section 60 acquires animage of an environment in which, for example, at least either acommunication device (the HMD 12 in the current example) or acommunication partner for the communication device (the relay device 16in the current example) is placed. The image acquisition section 60acquires an image captured by the camera section 44.

In the present embodiment, based, for example, on an image acquired bythe image acquisition section 60, the frequency band determinationsection 62 determines the frequency band of radio waves used forcommunication between the communication device (the HMD 12 in thecurrent example) and the communication partner (the relay device 16 inthe current example). Here, as described earlier, depending on whetherthe HMD 12 and the relay device 16 are in the same room, the frequencyband determination section 62 may determine the frequency band of radiowaves used for communication between the communication device the HMD 12and the relay device 16. Further, based on the distance between the HMD12 and the relay device 16, the frequency band determination section 62may determine the frequency band of radio waves used for communicationbetween the communication device the HMD 12 and the relay device 16.Furthermore, depending on whether an image of the HMD 12 or an image ofthe relay device 16 is included in the image captured by the imageacquisition section 60, the frequency band determination section 62 maydetermine the frequency band of radio waves used for communicationbetween the communication device the HMD 12 and the relay device 16.Here, even when the HMD 12 and the relay device 16 are in the same room,the frequency band determination section 62 may determine the frequencyband of radio waves used for the communication depending on whether theimage of the relay device 16 is included in the image captured by theimage acquisition section 60. Moreover, the frequency band determinationsection 62 may determine the frequency band of radio waves used for thecommunication depending on whether the image of the HMD 12 is included,for example, in the image captured by the image acquisition section 60.

In the present embodiment, the communication control section 64exercises control so as to establish communication by using thefrequency band determined, for example, by the frequency banddetermination section 62. If, for example, it is determined that 60 GHzband communication is to be established, the communication controlsection 64 exercises control so as to let the first communicationsection 34 a establish communication. If, for example, it is determinedthat 5 GHz band communication is to be established, the communicationcontrol section 64 exercises control so as to let the secondcommunication section 34 b establish communication.

Further, in the present embodiment, the communication control section 64retains communication section identification data. The communicationsection identification data is used to manage whether establishedcommunication is provided by the first communication section 34 a or thesecond communication section 34 b. If, for example, the establishedcommunication is provided by the first communication section 34 a, thevalue of the communication section identification data is set to "1."If, by contrast, the established communication is provided by the secondcommunication section 34 b, the value of the communication sectionidentification data is set to "2." When the value of the communicationsection identification data is set to "1," the communication controlsection 64 may exercise control so as to stop the second communicationsection 34 b. Meanwhile, when the value of the communication sectionidentification data is set to "2," the communication control section 64may exercise control so as to stop the first communication section 34 a.

The following describes, with reference to the flowchart of FIG. 5 ,exemplary processing steps that are performed by the HMD 12 according tothe present embodiment when the frequency band is to be determineddepending on whether the HMD 12 and the relay device 16 are in the sameroom.

First of all, the image acquisition section 60 acquires an imagecaptured by the camera section 44 (step S101). When the camera section44 is capturing an image at a predetermined frame rate, for example, thelatest image captured by the camera section 44 may be acquired in stepS101.

Then, based on the image acquired in step S101, the frequency banddetermination section 62 determines the frequency band of radio wavesused for communication (step S102). Here, based, for example, on theimage captured by the camera section 44, the frequency banddetermination section 62 identifies whether the HMD 12 and the relaydevice 16 are in the same room. If it is identified that the HMD 12 andthe relay device 16 are in the same room, the frequency banddetermination section 62 determines that the frequency band of radiowaves used for communication is the 60 GHz band. If, by contrast, it isidentified that the HMD 12 and the relay device 16 are in differentrooms, the frequency band determination section 62 determines that thefrequency band of radio waves used for communication is the 5 GHz band.If an image of the relay device 16 is included in the image captured bythe camera section 44, the frequency band determination section 62 maydetermine that the HMD 12 and the relay device 16 are in the same room.Meanwhile, if an image of the relay device 16 is not included in theimage captured by the camera section 44, the frequency banddetermination section 62 may determine that the HMD 12 and the relaydevice 16 are in different rooms.

Next, the communication control section 64 verifies the frequency banddetermined in step S102 and the value of the retained communicationsection identification data (step S103).

If the frequency band determined in step S102 is the 60 GHz band, andthe value of the communication section identification data verified instep S103 is "2," the communication control section 64 changes the valueof the communication section identification data to "1" (step S104). Thecommunication control section 64 then exercises control so as to let thefirst communication section 34 a establish communication (step S105).The process illustrated in the current example then terminates. In stepS105, the communication control section 64 may start the firstcommunication section 34 a and stop the second communication section 34b.

If the frequency band determined in step S102 is the 5 GHz band, and thevalue of the communication section identification data verified in stepS103 is "1," the communication control section 64 changes the value ofthe communication section identification data to "2" (step S106). Thecommunication control section 64 then exercises control so as to let thesecond communication section 34 b establish communication (step S107).The process illustrated in the current example then terminates. In stepS107, the communication control section 64 may start the secondcommunication section 34 b and stop the first communication section 34a.

In the other cases, the process illustrated in the current exampleterminates. More specifically, if the frequency band determined in stepS102 is the 60 GHz band, and the value of the communication sectionidentification data verified in step S103 is "1," the processillustrated in the current example terminates. Further, if the frequencyband determined in step S102 is the 5 GHz band, and the value of thecommunication section identification data verified in step S103 is "2,"the process illustrated in the current example also terminates.

Processing then returns to step S101. Subsequently, steps S101 to S105are repeated. Steps S101 to S105 may be performed at predetermined timeintervals.

Further, as described earlier, in step S102, the frequency banddetermination section 62 may identify, based on the image captured bythe camera section 44, whether an obstacle exists between the HMD 12 andthe relay device 16 to block radio waves. If it is identified that anobstacle exists to block radio waves, the frequency band determinationsection 62 may determine that the frequency band of radio waves used forcommunication is the 5 GHz band. Meanwhile, if it is identified that noobstacle exists to block radio waves, the frequency band determinationsection 62 may determine that the frequency band of radio waves used forcommunication is the 60 GHz band.

Moreover, in step S102, the frequency band determination section 62 maydetermine the frequency band of radio waves used for communication inaccordance with the distance between the HMD 12 and the relay device 16.

The following describes, with reference to the flowchart of FIG. 6 ,exemplary processing steps that correspond to the above-described stepS102 and are performed by the frequency band determination section 62when the frequency band of radio waves used for communication is to bedetermined based on the distance between the HMD 12 and the relay device16.

First of all, based on the image acquired in step S101, the frequencyband determination section 62 identifies the distance L between the HMD12 and the relay device 16 (step S201). Next, the frequency banddetermination section 62 verifies the value of the communication sectionidentification data retained by the communication control section 64(step S202).

If it is verified in step S202 that the value of the communicationsection identification data is "1," the frequency band determinationsection 62 verifies whether the distance L identified in step S201 isgreater than a first threshold value (L1 + Δ) which is obtained byadding the value Δ to a reference distance L1 (step S203). Here, thereference distance L1 is, for example, 8 m, and the value Δ is a valuebased on the distance L identified in step S201, for example, 0.1 x L.The value Δ may be a value according to image-based recognition accuracyat distance L.

If it is verified in step S203 that the distance L identified in stepS201 is greater than the first threshold value (L1 + Δ) ("Y" at stepS203), the frequency band determination section 62 determines that thefrequency band of radio waves used for communication is the 5 GHz band(step S204). Subsequently, steps S103 and beyond are performed.Meanwhile, if it is verified that the distance L identified in step S201is not greater than the first threshold value (L1 + Δ) ("N" at stepS203), the frequency band determination section 62 determines that thefrequency band of radio waves used for communication is the 60 GHz band(step S205). Subsequently, steps S103 and beyond are performed.

If it is verified in step S202 that the value of the communicationsection identification data is "2," the frequency band determinationsection 62 verifies whether the distance L identified in step S201 issmaller than a second threshold value (L1 - Δ) which is obtained bysubtracting the value Δ from the reference distance L1 (step S206).

If it is verified in step S206 that the distance L identified in stepS201 is smaller than the second threshold value (L1 - Δ), the frequencyband determination section 62 determines that the frequency band ofradio waves used for communication is the 60 GHz band (step S207).Subsequently, steps S103 and beyond are performed. Meanwhile, if it isverified that the distance L identified in step S201 is not smaller thanthe second threshold value (L1 - Δ), the frequency band determinationsection 62 determines that the frequency band of radio waves used forcommunication is the 5 GHz band (step S208). Subsequently, steps S103and beyond are performed.

In a situation where the above-described scheme is applied, if thedistance L is greater than the first threshold value (L1 + Δ), thefrequency band determination section 62 changes the frequency band ofradio waves used for communication between the HMD 12 and the relaydevice 16 from a first frequency band (e.g., 60 GHz band) to a secondfrequency band (5 GHz band). Meanwhile, if the distance L is smallerthan the second threshold value (L1 - Δ), the frequency banddetermination section 62 changes the frequency band of radio waves usedfor communication between the HMD 12 and the relay device 16 from thesecond frequency band (e.g., 5 GHz band) to the first frequency band (60GHz band).

As described above, the threshold value of the distance between the HMD12 and the relay device 16 may vary depending on whether the frequencyband of radio waves used for communication changes from the firstfrequency band (high-frequency band) to the second frequency band(low-frequency band) or changes from the low-frequency band to thehigh-frequency band. Further, the difference (2 x Δ) between the firstthreshold value (L1 + Δ) and the second threshold value (L1 - Δ) may bebased on the distance L identified in step S201.

The present invention is not limited to the above-described embodiment.

For example, all or some of the functions illustrated in FIG. 4 may beimplemented by the relay device 16 or the entertainment device 14. Insuch an instance, control is exercised to determine whether the relaydevice 16 uses the first communication section 54 a or the secondcommunication section 54 b to communicate with the HMD 12.

Further, the frequency band of radio waves used for communicationbetween the HMD 12 and the relay device 16 may be determined based on animage that is captured by the camera 20 a to depict an environment inwhich at least either the HMD 12 or the relay device 16 is placed. Here,the frequency band of radio waves for communication between the HMD 12and the relay device 16 may be determined depending, for example, onwhether an image of the HMD 12 is included in the image captured by thecamera 20 a. If, for example, the image of the HMD 12 is included in theimage captured by the camera section 20 a, control may be exercised toestablish 60 GHz band communication between the HMD 12 and the relaydevice 16. Meanwhile, if, for example, the image of the HMD 12 is notincluded in the image captured by the camera section 20 a, control maybe exercised to establish 5 GHz band communication between the HMD 12and the relay device 16.

Furthermore, the present invention is not only applicable to switchingbetween 60 GHz band communication and 5 GHz band communication, but isgenerally applicable to switching between high-frequency bandcommunication and low-frequency band communication.

Moreover, the foregoing specific character strings and numerical valuesand the character strings and numerical values in the accompanyingdrawings are illustrated and not restrictive.

1. A frequency band determination device comprising : an informationacquisition section that continuously acquires information of anenvironment in which at least one of a communication device and acommunication partner for the communication device is placed; and afrequency band determination section that, upon the acquisition of eachinformation, determines from among a plurality of communicationstandards of frequency bands of radio waves, and based on the acquiredinformation, the communication standard to be used for communicationbetween the communication device and the communication partner, wherein:the communication partner outputs video and audio signals to thecommunication device, the information acquisition section continuouslyacquires the information at a predetermined frame rate, and thecommunication device includes at least one camera.
 2. The frequency banddetermination device according to claim 1, wherein the camera acquiresimages of a physical environment in which the communication device islocated.
 3. The frequency band determination device according to claim1, wherein the frequency band determination section determines thecommunication standard depending on whether or not the communicationdevice and the communication partner are in a same room.
 4. Thefrequency band determination device according to claim 1, wherein thefrequency band determination section determines the communicationstandard depending on whether the acquired information includes an imageof the communication device or an image of the communication partner. 5.The frequency band determination device according to claim 1, whereinthe frequency band determination section determines the communicationstandard in accordance with a distance between the communication deviceand the communication partner, the distance being identifiable from theacquired information.
 6. The frequency band determination deviceaccording to claim 1, wherein the communication partner is wired to theentertainment device.
 7. The frequency band determination deviceaccording to claim 1, wherein the communication device includes at leastone camera which acquires images of a physical environment in which thecommunication device is located.
 8. The frequency band determinationdevice according to claim 7, wherein the at least one camera is disposedon an edge of the communication device.
 9. The frequency banddetermination device according to claim 7, wherein the at least onecamera is a stereo camera.
 10. The frequency band determination deviceaccording to claim 7, wherein the at least one camera captures one of:(i) an omnidirectional image of surroundings of the physical environmentin which the communication device is located, and (ii) a directionalimage substantially only of the communication device.
 11. The frequencyband determination device according to claim 7, wherein the at least onecamera operates as a distance measuring device.
 12. The frequency banddetermination device according to claim 11, wherein the at least onecamera includes an infrared camera.
 13. A head-mounted displaycomprising: an information acquisition section that continuouslyacquires information of an environment in which at least one of acommunication device and a communication partner for the communicationdevice is placed; and a frequency band determination section that, uponthe acquisition of each information, determines from among a pluralityof communication standards of frequency bands of radio waves, and basedon the acquired information, the communication standard to be used forcommunication between the communication device and the communicationpartner, wherein: the communication partner outputs video and audiosignals to the communication device, the information acquisition sectioncontinuously acquires the information at a predetermined frame rate, andthe communication device includes at least one camera.
 14. A method,comprising: continuously acquiring information of an environment inwhich at least one of a communication device and a communication partnerfor the communication device is placed; and upon the acquisition of eachinformation, determining from among a plurality of communicationstandards of frequency bands of radio waves, and based on the acquiredinformation, the communication standard to be used for communicationbetween the communication device and the communication partner, wherein:the communication partner outputs video and audio signals to thecommunication device, continuously acquiring includes continuouslyacquiring the information at a predetermined frame rate, and thecommunication device includes at least one camera.
 15. The methodaccording to claim 14, wherein the continuously acquiring includescontinuously acquiring the information at a predetermined frame rate.16. The method according to claim 14, wherein the determining includesat least one of: determining the communication standard depending onwhether or not the communication device and the communication partnerare in a same room; determining the communication standard depending onwhether the acquired information includes an image of the communicationdevice or an image of the communication partner; and determining thecommunication standard in accordance with a distance between thecommunication device and the communication partner, the distance beingidentifiable from the acquired information.
 17. The method according toclaim 14, wherein the communication partner is wired to theentertainment device.
 18. The method according to claim 14, wherein atleast one of: the communication device includes at least one camerawhich acquires images of a physical environment in which thecommunication device is located; the at least one camera is disposed onan edge of the communication device; the at least one camera is a stereocamera; the at least one camera captures one of: (i) an omnidirectionalimage of surroundings of the physical environment in which thecommunication device is located, and (ii) a directional imagesubstantially only of the communication device; the at least one cameraoperates as a distance measuring device; and the at least one cameraincludes an infrared camera.